The fourth trochanter is a shared characteristic common to archosaurs. It is a protrusion on the posterior-medial side of the middle of the femur shaft that serves as a muscle attachment, mainly for the musculus caudofemoralis longus, the main retractor tail muscle that pulls the thighbone to the rear.
The fourth trochanter is a shared characteristic common to archosaurs. It is a protrusion on the posterior-medial side of the middle of the femur shaft that serves as a muscle attachment, mainly for the musculus caudofemoralis longus, the main retractor tail muscle that pulls the thighbone to the rear.
Source: Wikipedia "Fourth trochanter" · CC BY-SA 4.0
Share this article: X · Bluesky